Wednesday, January 26, 2011


We must remember it took perhaps thousands of years for the human civilizations in various countries to discover the secret arts of fermentation until they have perfected the art of producing wine. The science and technological input into the field of fermentation technology have to await the discovery of Pasteur, Fleming and even the World Wars to push it forward to what it is almost today. In fact the structure of fermentor hardware has really remained unchanged even though the use of sensors, computers and engineering has influenced it. The increase in fermentation productivity is more from improvements in strain development
However, nowadays with the prolific offering of degrees in biotechnology and subjects like fermentation technology, the understanding and transfer of this technology seems to be very fast or take a very short learning curve. Having a degree in this field does not always automatically a fermentation technology expert. Especially in the field of fermentation technology more is learnt through trial and errors or through experience with the operation of the fermentor.
The true understanding of fermentation technology is not merely by reading books or lectures. Such approach will nly gives you the superficial scraping on the surface of the subject. This is often reflected by the students in only operating a standard lab model fermentor by following the attached manual or instructions. The manual does not teach you the way one should carry out any fermentation work or even in the design of experiments in fermentation.
It is at this point where the teacher or lecturer of the course must be able to teach the students the proper way to use and carry out the fermentation experiment
I have observed that most courses offered in fermentation technology stressed mainly in the operation of the fermentor according to the manual but failed badly in teaching the students how to exploit the fermentor as a powerful tool in research or teaching
Various upstream, downstream procedures, standard operating methods and validation are not executed. Practical fermentation technology by McNeil and Harvey should be a good starting point in understanding some aspects of the fermentor

Type rest of the post here. Read more!

Wednesday, January 19, 2011


One of the most consistent observations I have made in visiting institutions such as universities and research institutes in this country is the strong dependence on ready installed fermentors that are easily available from fermentor suppliers. These fermentors normally come completely assembled and with standard stirrers and sensors among others.
There seems to be poor attempts to remove or add certain components from the fermentors that are really necessary or unnecessary for the fermentation studies. It’s more the case of one fermentor ‘suitable’ for all applications. Or in a simple analogy one cooking pot that can be used to cook all dishes!
There are many advantages if we can modify our own fermtor
1 It allow our fermentor to be specifically configured purposely for our fermentation experiment
2 It allow us to cannibalize components from other fermentors which are no longer working to be reused in our fermentor
3 It allows us to add more components or sensors for the new fermentation process
4 It allows the use of our fermentor components to be used in other fermentor experiments
We get more savings and better utilization of our fermentor and ultimately giving us nore experience in managing and understanding our fermentor system
It is good if we have universal sleeves or adaptors to facilitate all these activities. Going to simple hardware shops will allow you to buy the same components at a much reduced price than what the fermentor vendor will provide
Additional components which we could add to our fermentor components should include various rotameters, peristaltic pumps, aquarium pumps, and even tachometer meters , ph meters ,among others and you will really see your fermentation activities becoming more productive and cheaper
Of course it is more ideal if you have your very own workshop to carry out the changes

Type rest of the post here. Read more!

Monday, January 17, 2011


Most fermentation studies are generally carried out under ambient pressure, despite the fact that the fermentor is often slightly positively pressurized. The slight positive pressure in most closed system fermentation studies are due to the aeration process of the fermentor, whereby air is forced to enter the broth or fermentation media for the microbial requirements. Positive pressure within the fermentation vessel is also due to the build up of back pressure due to the restriction of the exhaust gas vent.
The positive pressure is in many ways good for the fermentation process as it not only increase the solubility of air into the broth but also reduce the chances of external contaminants coming into the fermentation process. Of course there are also negative aspects of positive pressure on the fermentation process
High pressure does have the the effect of influencing the rates and direction of the metabolism of the microorganisms. This is especially so when in a particular way gases are products or side products of the pathway. High pressure in the fermentor will in a way prevent the formation or expulsion of the gaseous product into the surrounding fermentation media. This effect of preventing the release of the gaseous products will have the effect of interfering with the equilibria of the various biochemical reactions and may even result in toxicity of the internal environment of the cell and diversion of pathways.
How significant this impact will depend on many factors such as duration and intensity of the pressure applied.
One very important industrial impacts of high pressure fermentation will be on the production of organic volatiles. This is especially so in food and beverage fermentations. Often the taste, smell and characteristics of the fermentation products will determine its popularity and acceptance. If the fermented foods have lost or changed its volatile profile it might not be marketable.
While it is true these organic volatiles evaporate easily and are affected by the surrounding temperature, it is also the effect of the surrounding pressure to concentrate it within the closed fermentation system or let the valuable organic volatiles disappear into the environment.
What is important to know in detail now how does the high pressure exerted on the fermentation process affect the biochemistry and physiology of the process? Is there a way for us to control the direction of this fermentation by manipulating the fermentation pressure. Also important to know is how does high pressure fermentation in creating unwanted side side reactions or side products?
New designs in fermentors have to be created to accommodate the study on high pressure fermentation

Type rest of the post here. Read more!

Sunday, January 16, 2011


Teaching young university students is both an honour and a privilege. It is a real joy to teach these young and bright minds about fermentation technology. It is the duty or responsibility of the lecturers to ensure that they as their lecturers should be prepared and knowledgeable to impart the right knowledge on fermentation technology, to open up their minds and to bring out the best in the students.
These young students at such a prime age being exposed to university education are often not aware between what is right or what is wrong unless they are guided by their respective specialist lecturers. The lecturers should point out their mistakes and explain in interactive manner.
Most of these young students have often the wrong perception of their lecturers. In their eyes the lecturers are like giants and everything they say must be right.
I found it morally wrong if in classes such as fermentation technology which depends more on hands on exposures and going through the errors and tribulations of fermentation experiments be taught more by sales representatives of companies selling the fermentors. They are sales personnel and teaching is not their profession. They are not trained to carry out the fermentation experiments in a proper scientific manner. They might supply, set up and commission the fermentors. That remains that
Where are the lecturers who are teaching them? Giving notes or print outs does not mean anything in fermentation technology. Personally I have seen so many mistakes, errors not only in preparation of the fermentation process but in carrying out the monitoring. There is no clear conclusions that can be derived.
The experiments are not properly designed or carried out.
So what do you expect these graduates will be once they graduated from the course? Just pictures of them posing with the fermentors for their personal albums? How can these students later on compete to find the right jobs in fermentation industries when at the interview they will show blank faces when questions are asked?

Type rest of the post here. Read more!

Thursday, January 13, 2011


While it is generally true that fermentation technology is considered an advanced course and only be taken in final years of the biotechnology or microbiology degree, that does not always mean that fermentation technology could not be taught at the lower years such as in schools and colleges. The depth and complexity of the course at the degree and non degree level might be different as befitting the target students. However, the excitement generated in getting to know this ‘ancient course’ might be over whelming!( I did say it is an ancient course because fermentation was discovered and applied thousands of years ago by our ancestors.)
In my years of teaching the fermentation technology primarily at university level and on pro bono basis at schools I have always observed that the students are very excited and attentive. The excitement is perhaps more due to the excitement of knowing how to ferment and distilling wine
Such courses are even more exciting when it is carried out ‘hands on’ and that they are able to get drunk drinking the very wine they made. You are forgiven if the fermentation technology lab begin to smell like a pub!
But the study of fermentation technology is more than just learning to brew. Learning to brew or making wine could be carried out by wine enthusiasts.
So if we are to conduct fermentation technology courses we have to be clear the type of students we are dealing with respect to their age, academic background and level of understanding.
We would also have to know the purpose and objectives of the fermentation technology to be carried out.
The type of course syllabus would be very different for each group of target audience. More technical course would be proper for undergraduates or for those in academic lines. While simple fermentation demonstrations would be suitable for primary and secondary school students
While there are advantages in teaching science teachers the intricacies of fermentation technology such as the amplification of knowledge when the teachers passed the knowledge down to their students, the negative aspects are the lack of enthusiasm shown by the teachers. After all its is difficult for old dogs to learn new tricks!
Teaching young eager, inquisitive and curious students will leave clear imprints on their lives on what they have acquired by learning hands on in fermentation technology.
Personally I would opt for the latter, as the dividends would be more immense…..!!!!
It is a known fact that not just anyone can teach or be a good teacher. For herein lies the problem of the scientist being the sommunicator ( or even entertainer). He has the duty of not only teaching but imparting the enthusiasm
It is a known fact that the typical secondary school laboratory has a very limited and fundamental equipments used in their general laboratory teaching. Common equipments might include microscope, ph meter, autoclaves, thermometer, weighing machines, Bunsen burner and simple spectrophotometer perhaps
These laboratories are not specifically designed for fermentation technology. As such to carry out such courses you have to adapt to the limitations
Well. It is good if we have the necessary laboratory equipments, but that does not mean we cannot carry out fermentation technology with just the simple equipments we have? We must be creative and learn to think out of the box in order to carry out the fermentation technology practicals.
It doesn’t take much to think of simple PET or used Coca Cole bottles, tubings and bungs to come up with something!
We have a diversity of fermentation models from which we can extract more details and data for understanding fermentation technology. It need not only be wine! . We can study:
1 Bread fermentation
2 Tapai fermentation
3 Tempe
4 Yogurt
By measuring some parameters such as changes in temperature, volumes of gas proced and even weight we can plot a lot of interesting graphs
Visiting fermentation industries could be very rewarding after conducting such courses and see fermentation technology in action!

Type rest of the post here. Read more!


Dear Colleague,

The Journal of Brewing and Distilling (JBD) is a multidisciplinary peer-reviewed journal published monthly by Academic Journals ( ).JBD is dedicated to increasing the depth of research across all areas of this subject.

JBD welcomes the submission of manuscripts that meet the general criteria of significance and scientific excellence in this subject area, and will publish:

· Original articles in basic and applied research

· Case studies

· Critical reviews, surveys, opinions, commentaries and essays

We invite you to submit your manuscript(s) to for publication. Our objective is to inform authors of the decision on their manuscript(s) within four weeks of submission. Following acceptance, a paper will normally be published in the next issue. Instruction for authors and other details are available on our website;

Editors and reviewers
JBD is seeking qualified researchers to join its editorial team as editors, subeditors or reviewers. Kindly send your resume to .

JBD is an Open Access Journal

One key request of researchers across the world is unrestricted access to research publications.Open access gives a worldwide audience larger than that of any subscription-based journal ad thus increases the visibility and impact of published work. It also enhances indexing, retrieval power and eliminates the need for permissions to reproduce and distribute content. JBD is fully committed to the Open Access Initiative and will provide free access to all articles as soon as they are published.

Best regards,

Emebane Excel

Editorial Assistant

Journal of Brewing and Distilling (JBD)


Type rest of the post here. Read more!

Wednesday, January 12, 2011


Prior to building any fermentation facilities especially in the case of producing new fermentation products, upgrading or even transforming the existing fermentation facilities to produce other fermentation products, it is important not only to carry out in depth studies before committing to the project. This is important not only in cutting the risks but to ensure that the project will be successful.
One of the requirements at this stage is to produce the fermentation process flow chart. The flow chart will show the relationships between all the essential components right from upstream to downstream activities, The process flow chart is like a road map or the architectural blue print of all the units involved. However such flow charts are not that detailed enough to include in detail minor components or parts of the systems. Process flow diagrams for multiple units do not include detailed information and are known as the schematic flow diagrams or block flow diagrams.
The essence of the flow chart at the moment is that it is sufficient enough to allow discussions between various parties involved in the project and all those involved before any commitment is made
Producing a process flow chart require a lot of collaboration between many members of the team. Each member will be doing something which will be further worked upon by other members of the group. There will be a lot of research in literature, further experiments to carry out, following rules of the thumb and various experiences derived from other projects. All this will be incorporated into the input of the process flow chart.
It will need the input of various professionals from microbiologists, biochemists, chemists, engineers , economists and even computer experts
Well, the journey of a thousand miles has to start somewhere.
The first step usually involves understanding the biochemical or microbiological reactions involved. Strong emphasis will be in the laboratory work to acquire sufficient data on the process. At this stage effect of various parameters, type of substrates used, operating conditions, scaling up and stoichiometry studies have to be carried out.
The various unit processes involved from upstream to downstream have to be identified and positioned.These data could easily be obtained from various sources. The problem is for each unit process proposed detailed optimum conditions of the operation of the unit processes must be achieved
The flow from upstream to downstream must be smooth and no bottle necks or under utilization is created

Type rest of the post here. Read more!

Tuesday, January 11, 2011


In the earlier posts of this blog, we did cover briefly on the importance of the use of coloured dyes to visualize the flow pattern of the fermentation broth in fermentors. This experiment might be suitable for demonstrations to students taking fermentation course only .In that article we also discussed the various limitations of using selected tracers in visualizing the mixing or flow of the broth.
The importance of visualizing the flow is much more than like appreciating the fish in the aquarium. The ability to visualize really help understanding and highlighting problem areas in the fermentation process such as the efficiency of mixing.
Mixing could be improved in order to enhance the fermentation process to the optimum level. After all mixing of the fermentation broth is one of the most important parameters which affect the fermentation process. Mixing also affects other parameters such as mass transfers and heat transfers. Any change in the mixing regime will cause adjustment of the values of other parameters
The most powerful tool now in studying mixing in fermentors is no longer the use of coloured tracers but by the use of computational fluid dynamics (CFD). CFD is more a computer simulation program used to visualize the happenings during mixings It will become a powerful tool in the design and operation of the fermentors
CFD is important especially in trouble shooting the fermentation process and even in the scaling up and scaling down exercise . Areas that could be studied and improved includes fluid dynamics, transport phenomenon, heat transfer, phase transition, and rheology
So how can we visualize the fluid dynamics of a fermentation system? Well we are now aware of various computer programs that execute computational fluid dynamics. In these specialized programs numerical methods and algorithms are applied to solve and analyze problems that involve fluid flows and associated phenomena.
The key to the success of applying CFD depends not only having the right computer programs and computers but the various sensors and interphase that allow the input of the data from the fermentor to the computer. CFD might not be useful if we do not have the proper sensors to detect measure and transmit to the computer
The more important role of CFD in fermentation technology is in prediction of the behavior based on whatever data we have. But the process is not simple as:
1 There is the need to vary the boreactor operating regimes. This is especially so when stirring, volume and pumping have to be changed
2 Effect of a change in one parameter affecting other parameters
3 Secondary effects generated which could be critical such as bubble breakup, and coalescence mechanisms and even effect of shears on microbes
4 Immense data storage is essential when using CFD
Whatever problems faced computer simulation studies using CFD is the future answer in fermentation technology

Type rest of the post here. Read more!

Monday, January 10, 2011


Microbial contamination of fermentation processes could be serious and even critical in some fermentation industries. The presence of unwanted microbes could not only jeorpadise the safety and quality of the fermentation products as in the production of pharmaceuticals but also cause product spoilage and short shelf lives of the products with serious consequence in terms of economy and time wasted.
Strange it may seemed but quite a number of people sees the problem of contamination only at the level of mid stream fermentation and ignoring the input of microbial contamination at both levels of upstream and downstream activities. They are in the belief that once a fermentation product is formed microbial contamination is no longer a problem.
In reality, the seriousness of microbial contamination occurs at all levels and at all times. In fact it is even more critical if traces of microbial contaminations occur upstream as the microbial contaminants will have time to amplify over space and time. And you will find yourself dealing with a bigger problem of contamination if steps are not taken to minimize the contamination problems earlier.
Finished fermentation products are attractive as substrates to microbial contaminants downstream. To the microbial contaminants these finished fermentation products are good food sources to support their growth
Everytime microbial contaminations occur in the fermentation industries it becomes a nightmare for the operators. The consequence of such contaminations would often mean the rejection of the complete process in terms of fermentation products, fermentation media which have very serious economic consequence. Costly steps are taken not only to terminate the fermentation but in washing, cleaning and eliminating the source of contaminants. Labour, downtime loss is part of the price they have to pay!
This situation is even more critical in pharmaceutical fermentations.
One of the main sources of introducing microbial contaminants occur during the transfers from one stage of the fermentation process to the other. We will now discuss the problems of aseptic transfers or aseptic fillings of the finished fermentation products in detail
The most significant word which we must contend and understand clearly here is ASEPTIC. Aseptic describes the condition where the environment is free from the presence of microorganisms which might cause the contamination. In a way it almost describes a sterile environment or zone where the desired activity takes place.
This situation of being absolutely free of microorganisms is almost quite impossible to achieve, especially in the environment of the factory floor or the fermentation plant. At best we can control only a certain volume of space as being free from microorganisms where aseptic transfers can be quickly carried out
It is of importance to use a smaller room for aseptic transfers in terms if economy and efficiency
Surfaces in the aseptic room must always be clean sterilized or disinfected as a matter of routine procedure
Microbes being microbes are very ubiquitous and microscopic. They are not easily seen and are easily transferred by air, water and other medium. A slight turbulence will easily dislodge and transport them from one point to another. Thus sudden or lots of movements should be avoided in areas where aseptic transfer are being carried out.
This is especially important when supplying air into the aseptic filling room.
Additionally the air introduced into the aseptic filling room should be sterile and filtered using a suitable size filter that meet HEPA standard
Cutting the air movements and turbulence is an important step in preventing microbial contaminations. The use of laminar flow is very strongly recommended to avoid turbulence
One of the greatest source or reservoirs of microns are the workers themselves. The human body carries a lot of microbial flora especially on the skin and our respiratory system. A sick or infected worker will even harbor more unwanted microbes and a source of disease and infections
The more workers you have the more risks you will face with microbial contamination. Keeping the number of workers to a minimum during aseptic transfer is important in reducing microbial contamination
The use of clean sterile protective clothing and guard help in preventing transfers of microbial contaminants from workers to the products
If possible most of the aseptic transfers should be automated or semi automated to prevent contamination from the operator

Type rest of the post here. Read more!

Sunday, January 9, 2011


Fluid mechanics is accepted as the integral part of study in civil engineering. It is also an important component in the study of physics. The study of fluid mechanics, especially fluid dynamics will try to explain the behavior and properties of fluid in motion. While fluid mechanics is important in the design of civil structures such as dams and bridges, it is of similar importance too in the field of fermentation technology, especially in trying to understand the behavior of the fermentation broth in the fermentors. Knowing the fluid mechanics in fermentors not only allow us to design better fermentors but will also improve the efficiency of the fermentation process.
In fluid mechanics it is important for us to appreciate that water or liquid could show two different behaviours under different conditions applied. We could treat the behavior of water as particle as in Langarian theorem or as a moving packets or bodies of flowing water in restricted volume in accordance with Eularian concept. Both approaches have their strength and weaknesses.
How does fluid mechanics has to do with fermentors?
A simple observation will tell you that all fermentors are equipped with some stirring mechanism of some sort. It could be in the form of stirrers with impellers or it could even be in the form of simple gyrating movements or waves in the case of the disposable reactors or fermentors.
The objectives of these stirrings or mixings is to bring about uniform composition throughout the fermentor and to improve its various mass transfer processes. Poor mixings and mass transfers will always result in sub optimum fermentation process.
There are many attempts to improve the optimum fermentation process by improving the efficiency of it kLa. But the solution is not as simple as increasing the oxygen flow or input. Attempts to increase the oxygen flow will lead to negative secondary problems such as shearing of cells and increase in foaming!
The type of fluid dynamics generated within a fermentor could be very complex. It might not only involved primary, secondary and even turbulent flow within the fermentor. This situation is further compounded by the size and geometry of the fermentors involved and by the presence of barriers such as the baffles and other structures. In certain situation the interaction of these liquid flows within the fermentor could lead to cancellation or even strengthening of the flow pattern and shear forces.
As we have said earlier in the mixing of the fermentation broth there are also very complex mixing of various sold, gas and liquid phases which respond differently to the mixing process and will affect the efficiency of the fermentation process
So how do we try to solve the problem of fluid mechanics that occur in the fermentor? The most likely answer will be the use of computational fluid dynamics in helping design and even locate the areas that need further attention

Type rest of the post here. Read more!